We have tried some other glow stone products on the market and they all pale in comparison to AGT. Your glow stones produce a 50%-75% greater glow intensity & duration than ANY other other glow marble and glow glass chips we have ever tested.
— Dr. Eugene Tssui, Architect, Author, CA., USA
I have tried other glow stones on the market such as glass glow stones and THEY JUST DON'T GLOW! AGT Glow Stones have the brightest and longest lasting glow on the planet! Don't waste your money or time on anything else!
— Shane M. - Illinois, USA
If you are planning to put your glow stone in concrete - don't waste you money on glass glow stone like I did in the past... They only glow for an hour - MAX!!! The AGT glow stone I bought glows ALL NIGHT!
— Todd K. - AB, Canada